Comment by OceanTwo

Before taking this questline, be aware that it is 'phased' in Stranglethorn Vale. This means that those who are hated with Booty Bay will have to use a few tricks to complete it. Additionally, Quests and flightmasters are unavailable - you cannot complete the STV regular quests (if going for the achievement, for example).

Edit: they may have fixed this, but hated with Booty Bay can still be a challenge. However, if you are questing, logging out, leaving the zone, or various other 'quick fixes' can allow you to get the flightmasters and quest givers back.